[PATCH v2 3/4] drm/bridge: dw-hdmi: add cec driver

[Hans Verkuil]

Hi Russell,

Just two small comments below.

After that's fixed you can add my:

Acked-by: Hans Verkuil <hans.verkuil at cisco.com>

and:

Tested-by: Hans Verkuil <hans.verkuil at cisco.com>

(on my SolidRun Cubox-i).

On 07/31/2017 04:29 PM, Russell King wrote:
> Add a CEC driver for the dw-hdmi hardware.
> 
> Reviewed-by: Neil Armstrong <narmstrong at baylibre.com>
> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
> ---
>  drivers/gpu/drm/bridge/synopsys/Kconfig       |   9 +
>  drivers/gpu/drm/bridge/synopsys/Makefile      |   1 +
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 326 ++++++++++++++++++++++++++
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h |  19 ++
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     |  42 +++-
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.h     |   1 +
>  6 files changed, 397 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
>  create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h
> 

<snip>

> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
> new file mode 100644
> index 000000000000..52c9d93b9602
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
> @@ -0,0 +1,326 @@

<snip>

> +static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)
> +{
> +	struct cec_adapter *adap = data;
> +	struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
> +
> +	if (cec->tx_done) {
> +		cec->tx_done = false;
> +		cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);

Replace by:

		cec_transmit_attempt_done(adap, cec->tx_status);

This gets the counters right.

> +	}
> +	if (cec->rx_done) {
> +		cec->rx_done = false;
> +		smp_rmb();
> +		cec_received_msg(adap, &cec->rx_msg);
> +	}
> +	return IRQ_HANDLED;
> +}
> +
> +static int dw_hdmi_cec_probe(struct platform_device *pdev)
> +{
> +	struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
> +	struct dw_hdmi_cec *cec;
> +	int ret;
> +
> +	if (!data)
> +		return -ENXIO;
> +
> +	/*
> +	 * Our device is just a convenience - we want to link to the real
> +	 * hardware device here, so that userspace can see the association
> +	 * between the HDMI hardware and its associated CEC chardev.
> +	 */
> +	cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
> +	if (!cec)
> +		return -ENOMEM;
> +
> +	cec->irq = data->irq;
> +	cec->ops = data->ops;
> +	cec->hdmi = data->hdmi;
> +
> +	platform_set_drvdata(pdev, cec);
> +
> +	dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
> +	dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
> +	dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
> +	dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
> +
> +	cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",
> +					 CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
> +					 CEC_CAP_RC, CEC_MAX_LOG_ADDRS);

Add the missing CEC_CAP_PASSTHROUGH capability.

I think I am going to add a new define to media/cec.h:

#define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
			  CEC_CAP_PASSTHROUGH | CEC_CAP_RC)

to simplify this since these are standard capabilities.

But that's something I'll do later. For now just add CEC_CAP_PASSTHROUGH.

> +	if (IS_ERR(cec->adap))
> +		return PTR_ERR(cec->adap);
> +
> +	/* override the module pointer */
> +	cec->adap->owner = THIS_MODULE;
> +
> +	ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
> +	if (ret) {
> +		cec_delete_adapter(cec->adap);
> +		return ret;
> +	}
> +
> +	ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
> +					dw_hdmi_cec_hardirq,
> +					dw_hdmi_cec_thread, IRQF_SHARED,
> +					"dw-hdmi-cec", cec->adap);
> +	if (ret < 0)
> +		return ret;
> +
> +	cec->notify = cec_notifier_get(pdev->dev.parent);
> +	if (!cec->notify)
> +		return -ENOMEM;
> +
> +	ret = cec_register_adapter(cec->adap, pdev->dev.parent);
> +	if (ret < 0) {
> +		cec_notifier_put(cec->notify);
> +		return ret;
> +	}
> +
> +	/*
> +	 * CEC documentation says we must not call cec_delete_adapter
> +	 * after a successful call to cec_register_adapter().
> +	 */
> +	devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
> +
> +	cec_register_cec_notifier(cec->adap, cec->notify);
> +
> +	return 0;
> +}

<snip>

Thank you for writing this driver!

	Hans